Experimental and numerical study of fence effects on dust emission into atmosphere from open storage piles

The results obtained from the research on the behaviour of fences (solid and porous) in the protection against particulated material emission to the atmosphere from open storage piles, are presented. This research was carried out through computational fluid dynamics (CFD) simulation by software Ansys CFX-10.0 in 3D, with K-epsilon being considered in the turbulence model. The efficiency of the use of porous fences as a protection against the wind flow, which interacts with an open storage pile, is shown. The use of these fences (when porosity is ɛ=30%) allows the reduction of wind flow velocity which interacts with the pile in comparison with the case of no use of fences (when porosity is 100%). In addition, the use of porous fences makes the velocity vortex, which is formed between the solid fence (ɛ=0%) and the pile, disappear, reducing the particle emission to the atmosphere by 78%.     

利用封闭式块石护坡调节通风管路基阴阳坡效应

为研究多年冻土区通风管路基和通风管封闭碎石护坡路基在阴阳坡温度差异影响下,温度场的不对称特征和下部冻土上限间的差异,评价封闭块石护坡对通风管路基温度场的调节效果,利用北麓河通风管路基实测温度资料,并考虑气候变暖的影响,分别对这两种路基温度场进行数值模拟分析.分析结果表明,通风管路基具有一定的降温能力,但阴阳坡下冻土上限间差异显著,路基温度场呈现明显的不对称性;在通风管路基阳坡增加封闭块石护坡后,可以降低阳坡下土体温度,减小阴阳坡下冻土上限间差异,能有效调节路基阴阳坡效应.对第50年路基与天然地表交界处年平均热流密度的分析表明,增加封闭块石护坡后的路基结构优于通风管路基,且两种路基均处于吸热状态.     

FBG传感器在PHC管桩竖向静载试验中的应用

根据目前FBG传感器在混凝土管桩中的应用现状,介绍了FBG传感器的数据处理原理,针对试验中最易发生破坏的环节,提出了一种可靠的FBG传感器埋设工艺,结合现场PHC管桩竖向静载试验,将试验数据与传统电阻应变片测试技术相比。试验结果表明:FBG传感器存活率高达97.06%,测试数据可靠,测试精度满足工程要求,FBG传感器完全可以应用到PHC管桩竖向静载试验中。     

结构化地物的异质性分析及其计算方法

将具有明显空间结构的非连续性地物数据的结构分析研究,归纳为空间数据的结构化异质性分析问题。在此概念的基础上引用曲线论的方法分析了结构化异质性的变异函数的构成,得出变异距离受样本点间地物弧长及其空间复杂度共同影响的结论,由此推出变异距离函数的解析表达公式。之后给出了结构化异质性的实验变异函数的一种近似计算方法,该方法在样本合理分布的前提下一致收敛于真实变异值。最后介绍了结构化异质性模型在青藏铁路路基沉降数据的结构分析计算中的一个应用实例。     

基于高性能计算平台的地学集成模拟分析环境研究

随着计算科学在地学领域中广泛的应用以及地学各个学科模拟理论研究的发展,目前涌现出了一批功能各异的地学计算模型。地学工作者在科学研究中要快速便捷地熟悉和使用这些模型,迫切需要一个集成的模拟分析环境,即把硬件与软件结合,使用和服务结合,并关联相应的模型文献、驱动数据、处理工具、源代码等。在本文中我们基于高性能计算平台软硬件环境建设的工作经验和地学发展趋势,提出了基于高性能计算平台的地学集成模拟分析环境 GISE（GeoscienceIntegrated Simulation Environment）总体设计框架,并对该环境中核心部分进行了设计和详细介绍。GISE 将充分有效地集成各类模型资源,并将 HPC 服务和应用相结合,以期形成地学 e-Science 的核心信息平台。     

地学e-Science发展的回顾与展望

自 e-Science 提出之后的近 20 年间,地学 e-Science 在计算、网络和存储等信息技术的推动下,业已形成了基于数据、模型、计算、可视化分析和协同工作的地学研究框架,已经成为推动地学研究方法变革的驱动器。本文梳理和归纳了地学 e-Science 的发展过程和一些典型应用,总结了地学e-Science 的发展趋势,提出了简化的基于 3M 平台（Monitoring（监测平台）、Modeling（模型平台）、Manipulating（操作平台））的地学 e-Science 架构。从地学 e-Science 发展趋势上看,建立基于数据产生、采集、传输、管理的联合观测系统,形成完善的监测平台是地学 e-Science 的基础。建立数据分析、制备、同化和模型构建、集成与模拟的模型平台是地学 e-Science 的核心。建立基于高性能计算、可视化分析和协同工作环境的操作平台是地学 e-Science 研究的基本环境。     

MODIS地表温度产品的验证研究——以黑河流域为例

分析了影响MODIS地表温度产品精度的主要因素,并对这些因素综合作用下的MODIS地表温度产品的精度验证方法进行了回顾和比较。针对MODIS地表温度产品在干旱半干旱地区误差偏大的状况,以黑河流域为例,对MODIS地表温度产品进行了验证。用于验证的地面观测数据包括自动气象站红外辐射温度计数据和长波辐射数据。这里结合具体的...     

低温作用下岩石基本力学性质试验研究

以江西红砂岩和湖北页岩为代表，分别进行不同冻结温度（-20℃～20℃）和不同含水状态（饱和与干燥）下的岩石单轴压缩试验与三轴压缩试验。试验结果表明，温度在-20℃～20℃变化时，红砂岩和页岩单轴抗压强度与弹性模量都基本随温度降低而增大，但温度变化对红砂岩强度的影响大于其对页岩强度的影响，且岩石的含水状态对岩石的冻结强度影响显著。温度在-10℃～20℃变化时，2种岩石的c，φ值都随温度降低而增大，但温度对红砂岩的影响大于温度对页岩的影响。通过对大量的试验数据进行分析，得到一系列有意义的拟合曲线及其关系表达式，可为研究低温及冻融循环影响的岩石基本力学性质研究提供可靠的试验依据。     

An experimental study of the mechanisms of freeze/thaw and wind erosion of ancient adobe buildings in northwest China

The arid and cold climatic conditions in northwest China are favorable for the preservation of ancient adobe buildings, but intense freeze–thaw and wind erosion have resulted in the collapse of many of these unique structures. Simulation experiments indicated that when the number of freezing–thawing cycles was the same, wind erosion intensity increased with increasing moisture content in soil and that under the same moisture content condition, wind erosion rates significantly increased with increasing number of freezing–thawing cycle. Wind tunnel experiments showed that the application of 5% lithium silicate and 10% potassium silicate significantly improved resistance to wind erosion and hence may be a valuable part of the protection of ancient adobe buildings in the harsh natural environments of northwest China.      

Hydrogen bond directed assembly of oligothiophene/fullerene superstructures on Au(1 1 1)

We previously reported that a branched quaterthiophene donor chromophore functionalized with a phthalhydrazide hydrogen bonding (H-bonding) unit (MeBQPH) gives twofold more efficient bulk heterojunction organic solar cells (with C₆₀ acceptors) compared to a nearly identical donor incapable of H-bonding (MeBQPME). Here, scanning tunneling microscopy (STM) studies confirm the formation of MeBQPH trimer rosettes on Au(1 1 1) through phthalhydrazide H-bonding interactions that are sufficiently strong to compete with adsorbate/substrate interactions. The MeBQPME comparator molecule void of hydrogen bonding functionality does not similarly assemble on the metal surface. Complementary density functional theory (DFT) calculations facilitate a structural understanding of the MeBQPH donor assemblies and their strong stabilization through formation of six hydrogen bonds. STM studies also reveal the templated growth of C₆₀ on ordered MeBQPH monolayers with C₆₀ molecules preferentially occupying the threefold interstitial sites of the MeBQPH monolayer. This work supports the idea that H-bonding interactions can be used to control the morphology of organic donor–acceptor blends to potentially create efficient and stable bulk heterojunction photovoltaic devices.